The present invention relates to a head drum of a tape recorder and, more particularly, to a head drum having a weight balancing plate.
In a typical tape recorder such as a VCR or a camcorder, a head drum for scanning a magnetic tape while revolving at high speed is installed angled with respect to a tape running direction in order to record/reproduce information on/from the running magnetic tape.
Referring to FIG. 1, a conventional head drum 1 includes a stationary drum 2 fixed to a deck (not shown) and a rotary drum 3 rotatably installed above the stationary drum 2.
A magnetic head 4 is installed in the rotary drum 3. A portion of the magnetic head 4 protrudes through an opening window 3a of the rotary drum 3, and contacts the outer circumferential surface of the rotary drum 3 so as to record information on a magnetic tape 5 or read recorded information therefrom. The rotary drum 3 revolves at high speed. In general, a rotary drum of a VHS-type tape recorder revolves at a speed of about 1800 r.p.m. (revolutions per minute), and that of a DVC-type tape recorder at a speed of about 9000 r.p.m. In this case, when the weight of the rotary drum 3 is unbalanced, vibrations occur which exert a bad influence on the recording and reproduction of information on/from the magnetic tape 5 by the magnetic head 4.
According to the conventional technology, a balancing weight 6 having a predetermined weight is attached to the rotary drum 3 to balance the weight of the rotary drum 3. However, it is not only difficult to set the exact position and weight of the balancing weight 6, but it is also difficult to attach the balancing weight 6 to the rotary drum 3.
Another method for balancing the weight of the rotary drum is to cut away a portion of the rotary drum itself. However, it is difficult to control the position and amount of the cutting and also it takes quite a long time to perform this method. Furthermore, the cutting method may exert a bad influence on other components.